From Screening to Targeted Degradation: Strategies for the Discovery and Optimization of Small Molecule Ligands for PCSK9. Issue 1 (16th January 2020)

• Record Type: Journal Article
• Authors: Petrilli, Whitney L.; Adam, Gregory C.; Erdmann, Roman S.; Abeywickrema, Pravien; Agnani, Vijayalakshmi; Ai, Xi; Baysarowich, Jen; Byrne, Noel; Caldwell, John P.; Chang, Wonsuk; DiNunzio, Edward; Feng, Zhe; Ford, Rachael; Ha, Sookhee; Huang, Yongcheng; Hubbard, Brian; Johnston, Jennifer M.; Kavana, Michael; Lisnock, Jean-Marie; Liang, Rui; Lu, Jun; Lu, Zhijian; Meng, Juncai; Orth, Peter; Palyha, Oksana; Parthasarathy, Gopal; Salowe, Scott P.; Sharma, Sujata; Shipman, Jennifer; Soisson, Stephen M.; Strack, Alison M.; Youm, Hyewon; Zhao, Kake; Zink, Deborah L.; Zokian, Hratch; Addona, George H.; Akinsanya, Karen; Tata, James R.; Xiong, Yusheng; Imbriglio, Jason E.;
• Is Part Of: Cell chemical biology. Volume 27:Issue 1(2020)
• Page Start: 32
• Page End: 40.e3
• Publication Date: 2020-01-16
• Subjects: PCSK9 -- affinity selection/mass spectrometry -- proximity-driven click chemistry -- structure-based drug design -- CETSA -- targeted protein degradation; Biochemistry -- Periodicals; 572.05
• DOI: 10.1016/j.chembiol.2019.10.002
• Languages: English
• ISSNs: 2451-9456

Abstract

Summary: Proprotein convertase substilisin-like/kexin type 9 (PCSK9) is a serine protease involved in a protein-protein interaction with the low-density lipoprotein (LDL) receptor that has both human genetic and clinical validation. Blocking this protein-protein interaction prevents LDL receptor degradation and thereby decreases LDL cholesterol levels. Our pursuit of small-molecule direct binders for this difficult to drug PPI target utilized affinity selection/mass spectrometry, which identified one confirmed hit compound. An X-ray crystal structure revealed that this compound was binding in an unprecedented allosteric pocket located between the catalytic and C-terminal domain. Optimization of this initial hit, using two distinct strategies, led to compounds with high binding affinity to PCSK9. Direct target engagement was demonstrated in the cell lysate with a cellular thermal shift assay. Finally, ligand-induced protein degradation was shown with a proteasome recruiting tag attached to the high-affinity allosteric ligand for PCSK9. Graphical Abstract: Highlights: Unprecedented allosteric small-molecule binder to PCSK9 was identified using AS/MS Biased and unbiased hit-to-lead strategy identified binders through divergent SAR Demonstrated binding of lead compound to PCSK9 in a cellular thermal shift assay Developed lead compound into targeted degrader achieving 60% reduction of PCSK9 levels Abstract : Petrilli et al. describe the identification of high-affinity small-molecule binders to PCSK9 through two complementary hit-to-lead approaches. The lead compound was shown to bind to PCSK9 in a cellular thermal shift assay and subsequently developed into a targeted protein degrader.